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m @w am w G. H. DAVIS AND w. G. GRIFFIN. v 'AUXILIIIRY TRACTOR FOR MOTOR VEHICLES. APFLICAHDN FILED JAN-1|, I9I5, RENEWH) APR. 26. i9|9.

- 1 Patented May 11,1920.

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attorney G. H. DAVIS AND W. G. GRIFHN. AUMHARY TRACTOR FOR M0708 VEHICLES. AYPLIGAIJGJ ng n HTIsGaI-Infigcwzn APR. 26, me.

No Modeij I 340 024;, Patented-Ma 11, 19,20. MANUFACTURE OF HARD UARBUN- 4 SHtET SSHEET 2v Patented Mar. 23, 1886.

I P. MU M 3 Z 6. H. DAVIS AND W. GRIFHN. AUXIUAEY TRACTOR rue MOTGR VEHKCLES.

V AFPLHiAHON SHED SAN. H, 1915. RENFWED APR 25,1919. 1,340,024. t d y 11,1920.

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w--. y 10 14 M i 7 m u I utha ucqs O .AHUN HLH) mm. 11. 1915. RENEWED AFR. as. Hawf 13&(?'62 Patented. May 11,19

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UNITED STATES PATENT OFFICE.

GEORGE H. DAVIS, 0F PORTLAND, MAINE, AND WILLIAM G.' GRIFFIN, OF WASHING- TON, DISTRICT OF COLUMBIA, ABSIGNOBS, BY DIRECT AND MEBNE ASSIGNMENTS, OF ONE-HALF T0 SAID DAVIS AND ONE-HAL! TO EDWARD '1. BUBBJOWES, 0] PORT- LAND, MAINE.

AUXILIARY TN-ACTOB FOB MOTOR-VEHICLES.

Patented May 11, 1920.

Application filed January 11,4915, Serial No. 1,811. kencwed April I6, 1819. Serial Ho. 298,016.

To all whom it may concern: I

Be it known that we, (inouos ll. DAVIS and WILLIAM G. Guirrm, citizens of the United States, residing, respectively, at

Portland in the county of Cumberland and State of Maine, and at \Vashington, in the District of Columbia, have invented certain new and useful Improvements in Am:- iliar Tractors for Motor-Vehicles, of which the ollowing is a specification.

This invention relates to an auxiliary tractor device for motor vehicles.

As is well known, motor vehicles are usually propelled by means of the rear wheels, the iront wheels being pivoted so that the direction of movement of the vehicle may be controlled. The thrust or driving effort of the rear or traction wheels, is, of course, always exerted straight ahead, and when the front wheels are turned at a sharp angle only a very-small component of this thrust is available in-the direction in which the wheels are set. On this account it is extremely diflicult to make short turns with such vehicles, especially heavy trucks.

Moreover it is often necessar or desirable that, in loading; or unloading reightmelpr vehicles enter very narrow or restricted front of such machines laterally, as can be done with most horse drawn vehicles.

'1 he main object of the present invention is, therefore. to provide an auxiliar tractor attachment by means of which t c front wheels (if a vehicle can be lifted clear of the ground and the front end ofthe vehicle swung laterally and bodily around, as may be desired. By this means it will be possible to shift the vehicle free of obstructions, and set it in such position that theusual rear traction wheels can effectively propel it.

Another object is to provide an auxiliary tractor which may be readily attached to existing types of motor vehicles, without may be made to operate in a number of different ways, either by hand, by an independent motor, or by power derived from the main propelling means on the vehicle. Therefore, the accompan ing drawings, forming part of this speci cation and CllS- closing several embodiments of the invention, are to be re arded as illustrative onl In order that t c invention may'be clear y understood, reference is had to such drawin s, in which,

igure 1 is a front view of a motor truck showing our auxiliary tractor device attached thereto, amlillustrating the same in operative position; v

Fig. 2 is a fragmentary side elevation of the truck and tractor, parts being in section and parts being broken away;

Fig. 3 is a central longitudinal section on an enlarged scale, throu 'h the tractor itself,

showing one method 0 drivin the same;

Fig. 4 is a front elevation o the tractor shown in Fig. 3;.

Fig. 5 is a plan view thereof;

Fig. (i is a fragmentary section, similar to Fi 3, but showing a different method of driving the tractor wheels;

Fig. 7 is a horizontal section substantially on the line 7-7 of Fig. 3;

Fig. 8 is a side elevation, partly in section, showing another method of mounting the auxiliary tractor on the vehicle, and illustrating the same in operative position 5 Fig, 9 is a front elevation thereof, illustrating the device in'inoperative position;

Fig. 10 is, horizontal section substantially on the line 10-10 of Fig. 8; and,

Figs, 11 and 12 are conventional sile elevations of the tractor, showing the same in different positions, and illustrating one method of bringing the device into operation.

Referring to the drawings in d tail, I designates the usual front axle of a motor vehicle such, for example, as a deliver truck. 2 indicates the front wheels, whic 1 may be mounted on pivoted stub spindles in a well known manner, 3 designates the usual steering rod connecting the front wheels so that they may be turned in any engage the underfac'e of the section- 5.

desired direction by means of suitable steering gear (not shown).

Our auxiliary tractor device is designed to be attached directly to the front axle, substantially at its middle. In order to furnish convenient and efficient means for securing the tractor to the axle, weprovide a bearing member formed of upper and lower sections 4 and 5, adapted to be clamped around the axle by means of bolts 6, as clearlyshown in Figs. 3, 4, and 5. The

lower section 5 is providedwlth a central depending boss 7, the lower end'of which is' screw-threaded.

A block 9 is swiveled on the boss 7, and is secured in position by means of a suitable washer and nut 8, engagin the screwthreaded end of the boss 7. '-lhe upper surface of, the block 9 .is cut to form a race-' way for suitable ball bearings 10,- which 1c elements 5 and. 9 are preferably provided with concentric overlapping flanges I1 and 99, respectively, for the purpose of fifltflllb ing the balls in position and excluding dust and dirt. While the above described construction of swiveled block is strong and .elficient, it will, of course, be understood that other constructions may be employed without departing from the spirit of the in- Projecting from opposite block 9 are trunnions 11,- on which are ivotally mounted the side members 12 of a ork or bracket which carries the tractor rigidly secure a worm gear 18;

Meshin with this worm gear .is aworm 19, suit. 1y journaled at one endv 'in a bracket 20,-supported by the side members 12 and directly oou led at its'otherend to the armature 21-0 an electric motor 22. This motor is so ported between, rearwardly pro'ecting chee' re erabl era 12. n fact each piece comprising the members 12 and 12*]may be conveniently ,pressed from sheet steel.

At ouerside of the trunnions 11', the block 9 carries-a air of alined cylindrical bosses 23, and Mt e other side the block is formed with an opening adapted to receive a similarl shaped pin 24, thebosses 23 andpin 24 ying para lel with Len-ch other and with the trunmons 11. 'Each ofthe members 12 is formed at its upper end with concave sides of the ably 'proplates or extensions 12", formed integral witlrthe mem-.

suitable chain 27, or the like. By suitably I bosses 23 and pin Q4, respectively.

.In order that thqytractor wheels may. be

turned in any desired direction so as to guide the machine, we preferably provide means by which they may be opcratcd through the usual steering gear of the ve hicle. To this end, a plate 28 is scoured between the side members 12, and provided with a central forwardly extending ortion 29, having an elongated slot 30. n this slot is secured the stem of a small yoke or fork 31, which is adaited to enga,e the steering rod 3, as clearly shown in Fig. 3. The yoke is adjustable on the plate 28, so as to enable it to be accurately positioned relative to the steering rod. Collars 32.nrc secured to the steering rod 3, atcuch side of the yoke 31, as shown in Fig 7.

The electric motor drive illustrated in .Figs. 3, .4, and 5 is especially adaptcd for ill) p ant, By reference to Fig. 6, it will be seen thatthc same worm 19 is employed,

being supported by suitable brackets 20 and 20', and provided at one end with a coupling 33, to which is secured one end of a suitable flexible shaft 84. This shaft (see Fig. 2) ma be supported in suitable brackets 35, 'am connected at its other end with a counter-shaft 36, carrying a gear 37, sup

'ported in any convenient Way upon the usual gear box 38, and in mesh with a low Speed gear in said box. The gearing in the box 38 is, of course, driven by means of the usual engine (not shown) in the casing 39.

Normally the pin 24 is removed and the tractor swung roarwardly and upwardly about the trunnions 11 tothe position indidated by dotted lines in Fig. 11, in which, position it may be retained by means of adesignin the parts, the tractor may be arrange to swing as high abovethe ground as may be found nry. When. it is desired to use the device, the chain-is unhooked and the tractor allowed to swin 1 downinto the position shown in Fig. 1%

Power is then applied to the tractor wheels,

either by means of the electric motor 22', or the flexible shaft 34, so as to turn them inthe direction inrlicatedhy the arrow. This i will 'tlllmf thr whirls to travel forward and lit) means being controlled by the driver.

form tl'iemsclrcs under the axle, swinging the .ackct 12 about the trnnnions 11 until th dionidcrs if: engage the bosses 23, thus excl-ting a kind of toggle action and lilting lhr front wheels :2 clear of the ground, as illusirmrci in Fig. 12. in other ords, lw we 7' at the front part of the li o-ll Zr. iluw umd from the front wheels lo the (rm tor a i- '1 i The pin 2-1 is then inscrtcd in ii," is made for it, thus securing thc hrvc lict ri; by in position. Therenpon. lhr starring wheel may be turned so as to sex the tractor at any desired angle, and than upon applying power to the whccis. {hr trout ol' the vehicle will he carricd around as far as may be necessary to l'lllil' llnrilnlrurlion. It will be understood. ol' cours that when the tractor brarhrl: lsl ivs from the position shown in Fig. ll to that i lustrated in Fig. 12, the fork 3! is swung up into engagement with the steering rod 2.-.

it will also apparent that while we have illustrat d and described a tractor as being; opcratml by the usual steering gear of hrvehicle, special auxiliary steering gear may be proiidcd if desired.

Tnsl'cad of forcing the tractor under the axle by its own power as above cscribcd, means may he provided for positively raising and lowering the tractor wheels, such In we have illustrated such l igrs. 8 fl, and il an arrangement. lici'rrring to lhcse figures, ll) designates a block or braclnl which may be secured to lill axle l in an desired manner, as, for example, by bolt ll. and which projects to our side of said axle. In the lower part of the block 40 are formed a plurality of guidmvays 42, into which guidcways loosely extend. pins or rods 43, which are rigidly secured to and carried by a plate 44. similar plate is secured to the plate 44, as by means of bolts -46, and has a swivcled connection with the block 9, which carries the tractor. The block 40 is provided with a centrally disposcd screw-threaded open-i ing through which works a shaft 4 having a lhrcadml portion 47, and provided at its lower and with an annular collar or shoulder whi h is rigidly held in a pocket between :luplates 44 and 45. 'lo the up- 11c! nd of theshalt l!) is secured a suitable hand win-cl 51H. downwardly opcning hook Z-l is second to the side members l2 oi the lrart 'ir brackct. and is adapted to ,3: illr starring rod 3. l ormally thiwhccl Till is turnrd so as to hold thr tractor at the upper limit of its as illustrated in Fig. 5 the belo lhcn swung upwardly and ra-arwardly about the trunnions ll. and hooked up to a hain or the like so that am Is clearance between the tractor wheels an roadway will be provided. The relative osition and roportion of the parts 3 an 51 is such t at this swinging movement is permitted. When it is desired to tical movement. It will be understood that,

as the tractor is forced downwardly, the hook 51 engages over the steering rod 3, and that in its final )osition the front wheels of the vehicle are li ted clear of the ground.

The above described screw shaft arrangement is particularly applicable to electrically driven vehicles because in such vehicles there is no engine or transmission shaft, thus leaving a free space which can be occupied by the shaft 49.

It will, of course, be understood that other 1' orms of mechanism operated by either screws, levers, or cams, may be designed for positively raising and lowering the tractor from the drivers seat, such mechanism being actuated either manually or by power. The more or less conventional showin of Figs. 8, 9, and I0 is to be regarded as i lustrative only. 7

It will therefore be seen tlr". we contem date an auxiliary tractor device which can readily attached to the existing types of motor vehicles and which can be so controlled and operated as to lift the vlront wheels of the vehicle clear of the roadway and swing the front of the vehicle laterally, as may be necessary to effect a short turn or to avoid an obstruction. It is thought that the numerous advantages of the invention, as well as the many obvious modifications thereof which may suggest themselves to those skilled in the art,wi]l be apparent without further discussion} What we claim is:

1. The combination with a vehicle of an auxiliary tractor device therefor, said device including a bracket pi votally secured to an axle of the vehicle to swing about a vertical axis, said bracket comprising a. air of vertical side members, a horizonta shaft passing through the lower end of said members, a pair of rigidly united, spaced ground whccls mounted on said shaft between said side members, a worm wheel located between said ground wheels and rigid therewith, and a horizontal worm engaging said worm wheel and journaled in said bracket.

2. The combination with a. motor vehicle having the usual front wheels and steering gear therefor. including a horizontal stecr ing rod. of a bracket secul'rd to said vohicle between said wheels, said bracket be ing pivoted to swing rearwardly about a braeket is swung into vertical, operative position.

3. The combination with a vehicle having the usual wheels, of a bracket pivotall secured to the front axle thereof, an auxi iery tractor wheel mounted at the lower end of said bracket and adapted to be brought into engagement with the ground, and a motor operatively geared to said tractor wheel,

said motor bein also mounted on said bracket and parts ing of the pivotal move- 15 ments thereof.

In testimony whereof we have aflixed our signatures in presence of witnesses.

GEORGE H. DAVIS WILLIAM G. GRIFFIN. Witnesses as to Davis; C. B. Bmmowns, H. R. SEAVEY. Witnesses as to Griflin:

Rommr WATSON, *J. H. BOYDEN. 

